The invention generally relates to a probe assembly for contacting test points on semiconductor device chips and, more particularly, to a modular probe assembly easily adaptable to various high density test point patterns.
Multiple buckling beam probe assemblies are well known in the art for contacting test points on very small scale electrical structures, such as semiconductor device chips. In varying degrees, techniques have been proposed for contacting closely spaced points on irregularly elevated surfaces by means of probe wires which are caused to deflect or buckle as pressure is applied to the probe assembly. For example, U.S. Pat. No. 4,622,514 for Multiple Mode Buckling Beam Probe Assembly, issued to Stephan P. Lewis on Nov. 11, 1986, discloses a multiple probe assembly wherein each probe is guided by a series of spaced parallel plates. Even numbered plates are apertured by small holes which slidably engage respective probe wires. Odd numbered plates are apertured by large holes which permit buckling beam deflection of the probe wires when the probes are brought to bear against a device under test. All plates are held together at their ends to form a unit. Thus, the probes are not completely contained and supported over their entire lengths but only at intervals at the locations of the spaced plates. No special provision is made for the rapid replacement of individual probes for customizing the pattern of probes to meet the differing test point pattern needs of differing devices to be tested.
The containment and support over the length of the individual probes are provided to some extent in the single-slotted tube designs shown in IBM.RTM. Technical Disclosure Bulletin "Trilead Connector Assembly Tool" by I. A. Auerbach and R. Bove, Vol. 23, No. 6, November 1980, pp. 2379, and in U.S.S.R. Patent SU-514-457 issued in the name of E. E. Onegin on Feb. 4, 1974. In both cases, each probe wire is placed within a singly slotted tube. When the tip of the probe wire is pressed against a respective test point, the wire is caused to buckle and penetrate through the slot in the tube. An unslotted outer tube limits the maximum buckling in the case of the cited Technical Disclosure Bulletin. No restricting structure is illustrated in the cited U.S.S.R. patent to limit maximum buckling.
U.S. Pat. No. 4,843,315 for Contact Probe Arrangement for Electrically Connecting a Test System to the Contact Pads of a Device to be Tested, issued to Thomas Bayer, et al., on Jun. 27, 1989, describes a multiplicity of contiguous apertured plates for guiding the probe wires over a greater fraction of their length. Each plate is apertured by large holes which permit buckling beam deflection of the probe wires when they are pushed against a device under test. Even numbered plates are fixed so that all holes are in vertical alignment. Odd numbered plates are similarly fixed, but the aligned holes of the odd plates are offset relative to the aligned holes of the even set so that each probe wire contacts the opposed walls of contiguous holes when no devices are being tested. For ease of insertion of the probe wires into respective apertures, the plates are readjusted so that all of the holes are in vertical alignment. After the wires have been inserted, the even and odd plates are realigned into the hole relationship first described. Consequently, the ease of customizing the pattern of probes to meet differing test point pattern requirements is somewhat impacted.